Phytosociological Analysis in Semi-Arid Region of India: a Case Study from Yadgir District, Karnataka
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© Kamla-Raj 2018 J Biodiversity, 9(1-2): 14-24 (2018) PRINT: ISSN 0976-6901 ONLINE: ISSN 2456-6543 DOI: 10.31901/24566543.2018/09.1-2.064 Phytosociological Analysis in Semi-Arid Region of India: A Case Study from Yadgir District, Karnataka K. Bhaskar1, 2 and L. Rajanna3 1Centre for Ecological Economics and Natural Resources, Institute for Social and Economic Change, Bengaluru, Karnataka, India 2Research & Development Centre, Bharathiar University, Coimbatore, Tamil Nadu, India 3Department of Botany, Bangalore University, Bengaluru, Karnataka, India KEYWORDS Dry Land Ecosystem. Plant Diversity. Species Richness. Species Utilization. Vegetation Analysis ABSTRACT The present study covers structure, composition and distribution of vegetation in semi-arid ecosystem in respect of trees and shrubs and inventory of herbs. In the primary vegetation layer the highest density (individuals/hectare) was recorded for Prosopisjuli flora (133 individuals/ha) lowest for the species namely Dalbergia sissoo and Terminalia catappa (0.21 individuals/ha). The vegetation composition consists of 26.7 percent of tree species, 17.2 percent of shrubs, 42.5 percent herbs and 13.3 percent climbers forms the structure of natural ecosystems. The people of study region are using the plant diversity for various purposes for example medicine (78 species), fuel wood (26), fodder (23), edible (17), oral hygiene (11), timber (9), and other uses (3). Diversity indices for studied in semi-arid ecosystem found less than that of other ecosystems in India.The area available under forest cover is very less, that is, 3.64 percent of the studied landscape. Hence, strong conservation methods are required to protect the biodiversity for sustainable socio-ecological development. INTRODUCTION total geographical area falling in the semi-arid zone receives less than 750 millimetres of annu- Arid and semi-arid regions come under dry al rainfall with frequent drought conditions. landwhich are characterized by light inconsis- The varieties of factors were found to be tent rainfall of up to 700 mm per annum, periodic responsible for change in the vegetation dy- droughts and different associations of vegeta- namics in semi-arid regions. Food and agricul- tive cover and soils. The low amount of rainfall ture organizations reported that the population along with uncertainty in its pattern adversely growth of semi-arid region and poverty are the affects the development of dry land ecosystems. underlying factors determining land degrada- The arid and semi-arid regions constitute about tion and biodiversity loss in the semi-arid re- 65 percent of area of total dryland in the world gions. The existing plant diversity plays an im- (Nautiyal et al 2015). However, in India about 53 portant role in securing livelihood of the people percent land comes under arid and semi-arid re- and support the requirement of fodder, fuel gions which are highly vulnerable to climate wood, timber, non-timber forest products (NTF- change. In India, the semi-arid land spreads over Ps) and medicinal plants for the people inhabit- 9, 70,530 km2, of 99 districts of 11 states, this is ed in the dryland (Omuto et al. 2010). These dry- 37 percent of the total geographical area of the land (arid and semi-arid regions) cover more than country. In Karnataka, semi-arid land spreads more than 40 percent area of the earth surface over 1, 39,000 sq km, which is about 6 percent of and have the climatic uncertainties (Sharma the total geographical area of the country (Kalsi 2003) and the major distinguishing feature is the 2007). Therefore, Karnataka is second highest less rain fall and high temperature. The climatic state in terms of aridity after the Rajasthan (Mur- uncertainties and associated variations make the thy and Indumati 2011) where two-thirds of the differences between structures and functioning of the natural ecosystem therefore, socio-eco- *Address for correspondence: logical sustainability of the people living in K. Bhaskar semi-arid landscapes face lots of challenges.To Research Scholar, study the ecosystems, the phytosociological Bharathiar University, Coimbatore 641 046, Tamil Nadu, India studies are helpful in providing the information E-mail: [email protected] on vegetation composition, diversity of species, PHYTOSOCIOLOGICAL STUDIES OF SEMI-ARID REGION 15 distribution and comparison among the habitat are available on the phytosociological attributes types/ecosystems (Enright et al. 2005; Reddy et of ecosystems (Sharma and Pandey 2010; Pra- al. 2008; Kong et al. 2009). Various biotic and bakaran and Greeshma 2012).Therefore, in this abiotic factors influence the diversity and distri- endeavour, the present study was undertaken bution of the species in the natural ecosystems in the semi-arid region located in Karnataka of (Bargali et al. 2013). According to Nowak et al. India to explore the species diversity, distribu- (2017), one of the major factors for determining tion and their richness in the natural ecosys- the species composition in an ecosystem is soil tems along with landscape dynamics. salinity and humidity, elevation, slope and as- The objectives of the study were (i) To study pect and ecological studies revels that specific the species in their compositions, density, abun- plant communities like ferns and rare species dance, frequency, basal area and important value adaptations and also soil contaminated with el- index (IVI), and (ii) To prepare the diversity indi- evated levels of Co, Cu, Pb, Ni and Zn (Median- ces for the species of the semi-arid ecosystems. ista and Labay 2017). Therefore, study on phy- tosociological attributes is important aspect to Study Area and Climate be taken into consideration in ecosystem re- search (Enright et al. 2005; Kong et al. 2009). In forest ecosystems studies the phytosociologi- The study region is located in Yadgir district cal studies are foremost requirement for under- of Karnataka, India (16°72’58"N latitude and standing structure and up to certain extent the 76°74’19"E longitude), bound on the west by functional attributes in relation with human and Bijapur district, on the north by Gulbarga dis- plant interactions. The detailed database on trict, on the east by Maheboobnagar district of phytosociological studies is available for rich Telangana and on the south by Raichur district and diverse landscapes of India viz., the Hima- of Karnataka (Nautiyal et al. 2015). The average laya and the Western Ghats (Ralhan et al. 1982; elevation of the study area is 426 m from sea Saxena and Singh 1982). However, semi-arid re- level. The landscape which was taken for study gions remained isolated and only few studies is given in Figure 1. The temperature ranges be- India Karnataka Yadgir Yadgir Shahpur Shorapur 0 5 10 20 30 40 Kilometers Fig. 1. Geographical location of the study area 16 K. BHASKAR AND L. RAJANNA tween 44oC in summer to 24oC in winter and rela- The basal cover has calculated using the tive humidity varies from 20 percent during sum- following formula. Basal cover of a single tree mer to 60 percent during winter. The average BC=π*r2 rainfall is 650 mm and the normal rainy days range r=radius, π=3.14 between 42-50 days in a year. Species diversity (H´) has computed by the Shannon and Weiner (1963) information index METHODOLOGY as follows (eqn. 1): ni ni The study was carried dry deciduous forest H = log of Yadgir district in all the habitats. To analyse ∑ N n N the vegetation ecology in the study region, stan- Where, Ni is the total density value for spe- dard methodswere followed (Cottam and Curtis cies i and N is the sum of the density values of 1956; Ralhanet al. 1982; Saxena and Singh 1982; all the species in that site. Nayak et al. 2000; Nautiyal and Kaechele 2008; Beta diversity (b) among all the studied for- Hailu 2017). Transects were laid down starting ests was calculated following the method given from a base of the study area to end of the veg- by Whittaker (1975). etation zone in each selected site for various Sc habitat types. In each habitat, 30 quadrates in β = ∑ S triplicates (trees (10m x10m) shrubs (5m x5m) and Simpson’s Index (D) measures the probabil- herbs (1mx1m)) were plotted for primary data ity that two individuals randomly selected from collection (Nautiyal et al. 2015). The circumfer- a sample will belong to the same species (or some ence at breast height (CBH) was for tree species category other than species). at 1.37 m from ground level (Nautiyal et al. 2015). ∑n(n −1) However, in the case of shrubs, circumference D = N was measured at 10 cm above ground level. In- N = Total number of species, n= number of dividuals with diameter up to 3cm considered as species in one community seedlings and young tree with diameter of 3cm Evenness: Evenness is a measure of the rel- to 13cm and measureable about four feet above ative abundance of the different species making the ground considered as saplings. Herbarium up the richness of an area. specimens were prepared for all the species fol- lowing standard guidelines given by Botanical RESULTS AND DISCUSSION Survey of India (BSI) (Nautiyal et al. 2015). The primary data collected were analysed for fre- The quantitative analysis on plant diversity quency, density, abundance, and density/hect- of semi-arid region is essential to understand are. Basal area, relative dominance, relative fre- natural distribution and associated anthropo- quency and relative dominance were calculated genic pressure in such human dominating land- following the method given by Phillips (1959). scapes. With the help of detailed phytosocio- The sum of the relative dominance, frequency logical study, a total of 232 plant species be- and dominance gives the importance value indi- longing to 69 families consisting of 56 species ces (IVI) for various species (Curtis 1959).